diff --git a/rtl_wmbus.c b/rtl_wmbus.c
index fbee87e..18724af 100644
--- a/rtl_wmbus.c
+++ b/rtl_wmbus.c
@@ -789,7 +789,7 @@ static void print_usage(const char *program_name)
     fprintf(stdout, "\t-t 0 to disable time2 algorithm\n");
     fprintf(stdout, "\t-d 2 set decimation rate to 2 (defaults to 2 if omitted)\n");
     fprintf(stdout, "\t-v show used algorithm in the output\n");
-    fprintf(stdout, "\t-s receive S1 and T1/C1 datagrams simultaneously. rtl_sdr _MUST_ be set to 868.7MHz (-f 868.7M)\n");
+    fprintf(stdout, "\t-s receive S1 and T1/C1 datagrams simultaneously. rtl_sdr _MUST_ be set to 868.625MHz (-f 868.625M)\n");
 }